yes, it is possible. I would rather recommend using newest Hibernate and newest Envers, if possible. To do that, it is best to create a .ear or .war in an isolated classloader (you can do it through a special deployment descriptor), and bundle all hibernate jars in your application, leaving the AS libraries intact.
The exception suggest that you have a packaging problem, so that should help.
Migrated everything to jboss5.1.0 now - envers works like a charm now - well there are still some things that I need to figure out in envers, but at least it does what it should with a simple entity.
Thanks for the advice though!